An air strike killed at least 28 people in an Islamic State-held area of eastern Syria near the border with Iraq, the Syrian Observatory for Human Rights said on Friday.
The Syrian state news agency and the pro-Damascus al-Watan newspaper, in its online edition, said the U.S.-led coalition carried out the air strike near the town of Albu Kamal east of the Euphrates River.
The U.S.-led coalition could not immediately be reached for comment by phone and did not immediately respond to emailed request for comment.
Reuters could not independently verify the reports.
The U.S.-led coalition is fighting to crush the remnants of Islamic State in Syria in support of the Syrian Democratic Forces (SDF), an alliance of militias including the Kurdish YPG.